A green process PEG-600 mediated on-pot, alternative synthesis of 3-methyl-2-(((1-methyl-1H-benzimidazole-2-YL) sulfonyl) methyl) quinazolin-4(3H)-one

Abstract

Condensation of 2-((l H-benzo[d]imidazol-2-yl)thio)acetic acid (I) with anthranilamide (2) in PEG-600 (polyethylene glycol), at 100 °C for 3hr. gave 2-(((lH-benzo[d]imidazol-2-yl)thio)melhyl)quinazolin-4(3H)-one (3). Treatment of 3 with DMS, DES and Ph-CH₂-CI, individually in PEG-600, at RT ('or 1 hr. without using any basic, followed by easy process resulted in 4 (a-c). The later on reaction with H₂O₂ in PEG-600, for 3 hr, without using any base, followed by simple Processing resulted in 5 (a-c). Alternatively, 5 (a-c) the sequence of reactions could be prepared by tandem procedure with good yields. Thus novel quinazolinone products have been prepared with new synthetic routes and strategies by using PEG-600 as solvent, in polyethylene glycol (PEG-600) in four routes. i.e. (tandem-1, tandem-2, stepwise-l and stepwise-2) Probably, this is the first case of four variable but identical end-products- giving tandem syntheses, under green conditions, of 5 (a-c). Obviously, as figures pointed out, tandem-1 route gave good yields compared to the stepwise routes. In this process PEG-600 recycled and reused.